Poke Milkweed

Poke Milkweed
Asclepias exaltata

Poke Milkweed doesn't follow the rules for milkweeds; open sun and dense inflorescence. Instead, it grows in the woods and has a loose inflorescence that hangs downwards. The only giveaway is the individual flower structure with the five petals that point backwards and the five "hoods" that point upwards (downwards in this case).

This flower structure is highly developed to aid in pollination. Rather than explain it here, there are several references on the internet with detailed explanations, for instance here and here. You'll find it amazing to see the intricate design of this flower in order for it to successfully cross-pollinate.